This invention relates to a network system comprising a plurality of LANs (Local Area Networks) connected to an ISDN (Integrated Services Digital Network) via a plurality of routers.
In such a network system, each router is for use in connecting the LANs. Each router has a table for storing router information in connection with all of other routers except for the router in question. Each router is assigned with a router IP (Internet Protocol) address and a router telephone number. The router information indicates the router IP address and the router telephone number. Each router connects the corresponding LAN with another LAN through the ISDN by converting the router IP address specifying the other LAN into the router telephone number for the other LAN referring to the table. In order to connect among the LANs via the ISDN, each router must have the table storing the router information in connection with all of other routers except for the router in question, as mentioned before. It is assumed that a new router is added to the network system in order to connect the ISDN and a new LAN. In this event, each router must have the table storing the router information which is manually reset in prior art.